Functional annotation of paclobutrazol-treated mango rhizospheric soil reveals the recruitment of plant growth-promoting and xenobiotic compound-degrading bacterial species

Abstract

Context The soil microbiome governs plant and soil health through nutrient cycling, soil restructuring, degradation of xenobiotics, and growth regulation. Paclobutrazol (PBZ) is a plant growth regulator and is generally used for flowering induction, especially in alternate bearers like mango. However, the negative effects of PBZ on soil microorganisms and other living organisms are also linked to its excessive use and long-term persistence in soil. Aims We hypothesise that PBZ changes the soil microbial community and linked functions and consequently can alter agricultural productivity. Methods High-throughput sequencing was used to determine the shifting of functional diversity of bacteria in control and PBZ-treated soils of mango orchards. Key results The functional annotation of soil bacteria by COGNIZER tools revealed a higher abundance of genes, related proteins, enzymes, and metabolic pathways that are involved in either the degradation or efflux of xenobiotic compounds and nutrient recycling. Conclusions This research demonstrates how the application of PBZ modifies the rhizosphere’s functional diversity by recruiting microorganisms that aid in growth-regulating processes and, in turn, regulate arboreal phenology. Additionally, the microbial bioremediation of PBZ in mango orchards was established by this investigation. Implications The impact of soil microbial function in mango orchards may lay a scientific foundation for PBZ application and assessment of the PBZ influence on agricultural soil ecosystems.